Rust-inhibited petroleum distillate fuel



2,972,526 RUST-INHIBITED PETROLEUM DISTILLATE FUEL Fred K. Kawahara,Park Forest, 111., assignor to Standard Oil Company, Chicago, 111., acorporation of Indiana No Drawing. Filed Nov. 4, 1957, Ser. No. 694,113

2 Claims. (Cl. i t-64) This invention relates to a petroleum distillatefuel which is inhibited against rust formation and it pertains moreparticularly to an improved kerosene or heater oil composition.

An object of the invention is to provide an anti-rust additive fordistillate fuel oils and/or a distillate fuel oil composition which willinhibit the formation of rust in storage containers and/or in systemswherein the oil is exposed to iron surfaces. In other words, an objectof the invention is to provide a distillate fuel which will pass theiron strip anti-rust test, hereinafter described, by inhibiting rustformation for a period of at least 7 days in both oil and water phases.A further object is to provide such an oil in which the anti-rustcomponent is not prohibitive in cost and in which said component doesnot deleteriously affect other properties of the distillate fuel oil,i.e. one which will not be ruled out by ordinary distillate fuel oilspecifications.

My anti-rust additive is preferably a mixture of approximately equimolaramounts of a long chain condensed fatty acid material such, for example,as linoleic acid dimer and a hydrazone such, for example, as diisobutylketone hydrazone. The mixture may be marketed or used as a concentratebut in the ultimate distillate fuel it is present on a weight basis inamounts of the order of to 50, preferably about 10 to 30, parts permillion such, for example, as 5 pounds per 1,000 barrels of oil. Thecondensed fatty acid material is preferably a dimer and/or trimer oflinoleic acid, C H COOH, or a carboxylic acid material having similarproperties. By approximately equimolar I mean a molar ratio in the rangeof about 3:1 to 1:3. Other hydrazones which may be employed instead ofdiisobutyl ketone hydrazone (although not necessarily the equivalentthereof) are those obtained by reacting a hydrazine and a compound whereR and R may be hydrocarbon radicals such, for example, as methyl, ethyl,propyl, isopropyl, butyl, isobutyl, amyl, isoamyl, phenyl, etc., R and Rmay be the same or different radicals, and either R or R but not bothmay be hydrogen. Hydrazine derivatives containing such hydrocarbonradicals, i.e. dibutyl hydrazine, tributyl hydrazine or other alkylhydrazine may be em= ployed in place of the described hydrazones.

The distillate fuel to which my invention relates is a hydrocarbonboiling in the range of 200 to 700, and preferably in the range of 300to 600 F., and the preferred examples are kerosene and heater oil. Ithas been 'found, for example, that the invention is not applicable tocertain gasoline compositions and the advantageous results of theinvention are not necessarily attained with higher boiling oils. Thepreferred distillate fuels have an initial boiling point in the range ofabout 300 to 375 F., a percent point which is at least about 465 F. andan end point which is preferably in the range of about 500 to 650 F. Thedistillate fuel of my invention should have an A.P.I. gravity of atleast about 40 and a flash point by the Tag closed cup method not lowerthan F. and preferably above F. Such distillate fuel oils, e.g. keroseneor heater oil, may be stored in iron containers in the presence ofmoisture and it is desirable that no rust be formed on iron which iseither in contact with the oil or with a water phase. The following testprocedure was employed for determining anti-rust properties of variouscompositions: iron test strips were cleaned with emery cloth, then withfine sand paper and then with steel wool, after which each strip waswiped clean with a cellulose material and kept in a desiccator prior touse. The ends of the iron strips were cut to remove the portion whichmight not have been freed from rust. Into 100 ml. tall-form bottles Iadded a 50 ml. sample of the oil to be tested. Next the anti-rustadditive was introduced in the form of a 1 weight percent solution inxylene, 0.1 ml. of such solution being equivalent to 5 pounds ofanti-rust additive per thousand barrels of oil. Next the test strip wasplaced in the oil sample in the bottle for 30 minutes at an angle andthen 10 ml. of boiled, distilled water was added to each bottle and thebottles were stoppered with corks. Each bottle was rolled for one minuteand then allowed to stand upright for 7 days. Visual observation wasmade at 30 minutes, 4 hours, and other time intervals. Results of suchtests were as follows:

Efiect of additives in heater oil (5 lbs./1000 bbls.)

OIL PHASE 30 Min. 4 hrs. 16 hrs 7 days Commercial Additive Clean CleanClean Clean. Linoleic Acid Dimer+Dl-ido do do Do.

Butyl Ketone Hydrazone. Di-i-Butyl Ketone Hydra- Rust, 15 specks- RustRust, 7 spots Rust.

Z0118. Linoleic Acid Dimer Clean Clean Rust, 1 spot Rust, 1 spot.

WATER PHASE Commercial Additive Clean Clean Rust, 1 spot Rust-l-lronhydroxide precipitate. Llfioleifcld Dzine-r-l-DH- do do (lean Clean.

uty etone y azone. Di-i-Butyl Ketone Hydrado ..do Rust, 3 spots Rust.Liiililgie Acid Dimer do Slight Rust..- Rust Iron Hydroxide RustPrecipitate.

Precipitate.

containing a carbonyl group to obtain a product which may be representedby the formula R E=N-NH2 The commercial additive is one which isbelieved to be very good as an anti-rust in distillate fuels but it willbe 70 noted that when a water phase is present a rust spot developedwithin 16 hours and rust accompanied by iron hydroxide precipitate wasin evidence at the end of 7 days. My improved additive, namely linoleicacid dimer and diisobutyl ketone hydrazone in approximately equimolaramounts, resulted in clean iron test strips for the entire 7 days testperiod in both the oil and Water phases. Neither component of myadditive, however, is efiective by itself. The heater oil inthe aboveexample was a sweetened commercial product containing about 1 pound ofconventional metal deactivator per 1000 barrels. The anti-rust agents inthe foregoing tests were employed in amounts of about 18 parts permillon parts of heater oil on a weight basis; with some test oilseffective anti-rust may be attained with amounts as low as 5 parts permillion while other heater oils and/ or compositions may require as muchas 50 parts per million of the anti-rust material. In no case,however,is the treating cost prohibitive and in no case does the anti-rustmaterial dele teriously atfect other properties of the distillate fuel.

As another example of my invention, I may add an approximately equimolaramount of dibutyl hydrazine to a linoleic acid dimer or trimer andemploy the resulting composition in amounts of about 5 to 50 parts permillion in kerosene or heater oil.

I claim:

1. A distillate fuel of the heater oil boiling range which containsabout 5 to 50 parts per million on a weight basis of an approximatelyequimolar mixture of a condensed fatty acid material selected from theclass consisting of linoleic acid dimer, linoleic acid trimer andmixtures of linoleic acid dimer and trirner, and a compositionrepresented by the formula Rb=N-NH; where R and R are each selected fromthe group consisting of hydrogen and methyl, ethyl, propyl, isopropyl,butyl, isobutyl, amyl, isoamyl and phenyl hydrocarbon radicals and atleast one of said R and R is one of said hydrocarbon radicals.

2. A distillate fuel of the heater oil boiling range which containsabout 5 to parts per million on a weight basis of an approximatelyequimolar mixture of a condensed fatty acid material selected from theclass consisting of linoleic acid dimer, linoleic acid trimer andmixtures of linoleic acid dimer and trimer, and diisobutyl ketonehydrazone.

References Cited in the file of this patent UNITED STATES PATENTS

1. A DISTILLATE FUEL OF THE HEATER OIL BOILING RANGE WHICH CONTAINSABOUT 5 TO 50 PARTS PER MILLION ON A WEIGHT BASIS OF AN APPROXIMATELYEQUIMOLAR MIXTURE OF A CONDENSED FATTY ACID MATERIAL SELECTED FROM THECLASS CONSISTING OF LINOLEIC ACID DIMER, LINOLEIC ACID TRIMER ANDMIXTURES OF LINOLEIC ACID DIMER AND TRIMER, AND A COMPOSITIONREPRESENTED BY THE FORMULA